Change From Gt2835 Turbo To Gt3037 R33 Skyline

[Turbz RB-25]

Hi guys,

I currently have a r33 GTST skyline with 272 kw running a HKS GT2935 Pro S with all the usual mods (PFC, injectors, exhaust blah blah.).

Is it worth upgrading to the GT3037 Pro S? Or should I get cams instead?

Looking for around 330rwkw. or will the GT3037 not be able to push out 330rwkw?

Cheers

[BHDave]

cams won't gain you much as you are around the limit of what the 2835 can make. You might stretch it to around 280.

I can't say for certain the 3037 will make the power you are after but it will go closer than adding cams to the current set up

[Cubes]

GT3037 - You'll most likely need exhaust manifold + cams to get 320rwkw 'maybe' 330rwkw if you lean on it hard.

[discopotato03]

Arguably mild cams such as Tomi Pon Cams would allow you to get the most of what you already have and be a next possibly affordable step along the way .

There probably comes a time when trying to force as much gas into/out of a std head with std cams become self defeating .

Its the mid range torque/rush I'd be chasing rather than a max Kw figure .

Just my thoughts , cheers A .

[PIG747]

at what psi were you making 272kw with the 2835?

[blitza]

+1 for what cubes said. I think both.

[SLY33]

thats a nice healthy figure you have for stock cams. As mentioned adding cams wont get you a lot more, but as i found out with my own setup, poncams will give you 15+rwkw more through the midrange and a noticeable improvement in torque, not forgetting helping it spool earlier.

I find that for the street/city driving i do, my current peak of 280+rwkw is more than enough, and it will bag up in second gear just coming onto boost unless im on semislicks.

Im just about to see how much difference an extrude honed ex mani will make, if any..! (cubes, its still happening! just waiting on some half shafts from Nissan for the new OS diff centre to go in, and then its on the dyno for the re-tune)

speak of the devil, this just came through from my workshop!

"the orange one is all done just waiting to get on the dyno so should be good to go next week"

hopefully results very soon

Edited August 8, 2008 by SLY33

[Cubes]

Awesome sly33. Very keen to see the results.

Mines at 302rwkw with 256rwkw at 4K so its rather amusing in second. Still on stock inlet/exh. manifolds. I really hope this extrude hone is a go.

Who's doing the tune? The HKS2835ProS with cams manifolds etc is good only just for 300rwkw. Will be keen to see if it will manage it on the extrude honed exh. manifold.

[PM-R33]

Let us know how you go with an extrude honed manifold, will be interesting to see results.

[SLY33]

cubes thats an awesome result, your running a 3litre yeah? would your 2835 be the same as mine ex housing wise? (still not even sure what housing i have... which one does the HKS kit come with again?)

as i would have thought its a bit small for the extra exhaust flow from a 3litre?

Simon from Morpowa is tuning it, as he has done all my past tunes and ive been happy with each of them. Who tuned yours?

dunno if the honed stocker will give me an extra 20rwkw but will find out soon! will make a thread when its done.

cheers

[discopotato03]

I'd be looking around for one of the HKS cast low mount manifolds for an RB25 - or an RB25 head anyway .

One thing that would be interesting to know is if the Pro S bits all fit and work with the HKS low cast manifold .

From memory this manifold mounts the turbo a little further away from the engine and angles the compressor a little more towards the NS headlight .

If anyone has one of the Pro S turbos on the low cast manifold I'd like to see pics of the dump pipe to see how it clears everything .

Cheers A .

[wolverine]

i just installed legend01's old set up with extrude honed HKS cast manifold and extrude honed GT3040 front and rear. it is difficult to compare the set up against the standard gear but the extrude honing is dead sexy when you feel it.

the cast metal feels like oily glass after the extrude honing

i doubt an extrude honed manifold is worth 20kw but it seems to bring things on a little earlier and i guess with more even runner flow, tuning can be more accurate with more equal cylinder efficiencies?!?.

i am thinking about extrude honing my spare stock manifold to go on the other car at some point nevertheless.

[WARLORD]

just finished my 3037 pro s tune today at crd and it made 304kw atw and pulls damn hard all the way up to 8200 rpm but as for making 330kw on 98 octan fuel i dont think it can be done with out spending lots of $$$$.i had a long and interesting talk about the limit of this turbo today and if you realy want 330kw pick a larger turbo.i once believed that a gt-rs would make 300kw cos of some crap written on sau so do yourself a favour if you realy want to make 330kw and want real advice this turbo will not do it for you with out spending up.

[Cubes]

cubes thats an awesome result, your running a 3litre yeah? would your 2835 be the same as mine ex housing wise? (still not even sure what housing i have... which one does the HKS kit come with again?)

as i would have thought its a bit small for the extra exhaust flow from a 3litre?

Simon from Morpowa is tuning it, as he has done all my past tunes and ive been happy with each of them. Who tuned yours?

dunno if the honed stocker will give me an extra 20rwkw but will find out soon! will make a thread when its done.

cheers

Its a 3ltr, std inlet and exhaust manifolds. It pretty much topped out around 270-280rwkw before the cams. Dropped the cams in and went easily to 300 on 17psi.

The problem is it wouldn't hold any more than 17psi due to the weak actuator. It had the same issue before the cams making less power. 17psi was it.

The GT30 .82 exh. housing would be slightly larger than the 2835 I would presume.

I've known Sean @ Boostworx since he opened up shop so Boostworx it is. Motors done 90,000km's and hasn't let go so I'm confident of his tuning ability.

Warlord... To be honest the most I've seen out of the HKS3037S with a nice exhaust manifold, plenum and cams is 323rwkw on ~22psi with pump.

Al's RB30DET with cams, exhaust manifold and plenum has done 304rwkw on 16psi with more left in it as the motor has only just been run in.

No doubt that setup will pull 320rwkw hell maybe crack 330rwkw.

I'm going to push hard to crack 320rwkw with the std exhaust manifold even if it means extrude honing.

Unless I drop a GT35r on it and drop the setup in to a cheap R32 GTS4 aiming for high 300's I'm not going to bother with the HKS exh. manifold.

I've driven the car a bit now and absolutely hooked on its 200rwkw @ 3500rpm and 256rwkw @ 4000rpm.

From second gear it hooks up damn well. 16" tyres FTW lol. I've tried wider 18" tyres and there's no comparison when comes to straight line grip. The 18's just simply don't.

[WARLORD]

hi cubes,i have no doubt that it will make 330kw but i have spent big,if i piss the cat off and get a exhaust manifold ill get close but thats $1500 for a manifold and the spending continues all up with my engine re-build and parts and tunes im at a easy 18-20k now but at the end the day the package is unbelievable thanks to dart and crd and the spending has to stop somewhere,well thats what my wife has said.....lol....

Edited August 8, 2008 by WARLORD

[Cubes]

Well thats exactly it.. 20rwkw worth the non stock look and additional cost of a manifold. No thanks.

I really think the HKS3030ProS/GT3076r squeezes the absolute maximum out of the motor from a simple bolt on perspective.

18-20 is a fair whack.

Mine including the purchase of the head then rebuild/port polish etc set me back around 6k in total.

In total I've spent around 12k to get mine where it is now. Adds up damn quick.

[discopotato03]

Interesting thing this up to and around 290-300 Kw . Obviously the RB25 factory exhaust manifold will only go so far flow wise and I suppose HKS intended those Pro S turbos to live within its capabilities . Personally I think a GT3037/GT3076R 56T has more in it than 320 Kw but like most turbos it needs large A/R turbine housings to run it to its limit .

Cubes I would be very tempted to beg/borrow/steal a 1.06 A/R IW turbine housing because I think your 3 liter would be more free reving and with more advanced timing should gain in most areas except the very bottom end where it shouldn't be lacking anyway , what low WOT torque it lost may mean less traction loss at the same time in a RWD car .

Once you reduce the turbine inlet pressure you shouldn't have the IW issues because its the pressure and velocity that goes against integral waste gates , pressure wanting to force the gate open and high velocity meaning the gas not wanting to make the sharp right hander and flow out through the gates hole .

Not my money I know but food for thought , cheers A .

BTW I'll be trying for as close to 9.5 static CR and Pon Cams in my 33 25 because this has not been tried and I think pump fuels and turbos can nowdays cope with it .

[Al]

We'll see what she make by the end of the week

You are both spot on, so i'll not add to the discussion.

All i'll say is *cough* diff ratio *cough*

[Lithium]

just finished my 3037 pro s tune today at crd and it made 304kw atw and pulls damn hard all the way up to 8200 rpm but as for making 330kw on 98 octan fuel i dont think it can be done with out spending lots of $$$$.i had a long and interesting talk about the limit of this turbo today and if you realy want 330kw pick a larger turbo.i once believed that a gt-rs would make 300kw cos of some crap written on sau so do yourself a favour if you realy want to make 330kw and want real advice this turbo will not do it for you with out spending up.

I reckon this depends a lot on dyno, setup etc. What dyno were you running this one? Do you have high mount manifold/plenum/cams? How much boost?

I must admit I have never seen what these will do on an RB25DET though I am most keen to try and push mine hard at some point. I have seen Hondas/Mitsis getting well over 400whp/300kw @ wheels with these on pump gas on Dynojet and Dynapack dynos and mine has made 280kw @ wheels on pump gas without even really trying.

I am quite confident that I'd crack 330kw @ wheels on the turbo I have (.82a/r GT3076R) on a hub dyno with a decent manifold, cams and a decent hit of boost but the way the dynos read in Oz I'd consider a GT3582R for 330kw really - as much as anything just because a GT30R will definitely be at the high end of its capability on 330kw @ wheels whereas a GT3582R would be humming.

Edited August 9, 2008 by Lithium

[Al]

discopotato03: I believe you are spot on with the 1.06ar theory on the 3ltr. I am tempted, but will not do it, to fit one and see the difference. Seeing my car on the dyno, it is easy to determine that the GT30R with the 0.82ar housing is the restriction in the setup. While my car was being tuned, i could see the collector on the manifold glowing bright red, at an early rpm range, and the ETM manifold is also ceramic coated.

Don't get me wrong, i love the instant response and linear power characteristics, hence why i wont change it, but would be good to see how this all changes with a 1.06ar housing and an external gate .

I am happy at the level of performance, handling, and appearance my car is at and have decided to stop spending money on it.